1. Field of the Invention
The present invention relates to air flow meters. More specifically, the present invention relates to ion drag air flow meters or ion drag anemometers.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
High performance engines require precise measurement of air/fuel ratio to achieve optimum performance and to meet current emission standards. This function is performed by an air flow meter. The harsh environment of the automobile engine places significant restrictions on the design of conventional air flow meters. For example, the sensors of the meter must be able to withstand the extreme temperatures, humidities and pressures to perform adequately in a conventional internal combustion engine.
Many current air flow meter sensors are based on the principle of a heated wire or film placed in or adjacent to the air flow. These devices sense heat removal as air passes the wire or film. Those skilled in the art may appreciate that the limitations of these sensors include a lack of ruggedness, susceptibility to fouling and inability to sense flow direction. Further, the response of these sensors is often limited by the mass and construction thereof.
Further, few conventional sensors can actually measure air mass flow. This measure provides information on the amount of air mass which is being burned by the engine and is of considerable utility in the effort to achieve optimum engine performance.
Thus, there is a need in the art for an air flow meter for a rugged, high performance air flow meter capable of measuring air mass flow.